首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1720篇
  免费   70篇
  国内免费   19篇
耳鼻咽喉   19篇
儿科学   36篇
妇产科学   39篇
基础医学   130篇
口腔科学   53篇
临床医学   134篇
内科学   479篇
皮肤病学   10篇
神经病学   91篇
特种医学   65篇
外科学   418篇
综合类   11篇
预防医学   69篇
眼科学   86篇
药学   71篇
中国医学   1篇
肿瘤学   97篇
  2023年   9篇
  2022年   25篇
  2021年   58篇
  2020年   30篇
  2019年   51篇
  2018年   50篇
  2017年   28篇
  2016年   40篇
  2015年   38篇
  2014年   69篇
  2013年   72篇
  2012年   145篇
  2011年   182篇
  2010年   76篇
  2009年   88篇
  2008年   155篇
  2007年   140篇
  2006年   123篇
  2005年   90篇
  2004年   93篇
  2003年   74篇
  2002年   41篇
  2001年   14篇
  2000年   10篇
  1999年   5篇
  1998年   6篇
  1997年   13篇
  1996年   7篇
  1995年   6篇
  1994年   9篇
  1992年   4篇
  1991年   5篇
  1990年   3篇
  1989年   4篇
  1988年   5篇
  1987年   5篇
  1986年   2篇
  1985年   3篇
  1984年   2篇
  1982年   4篇
  1980年   3篇
  1979年   2篇
  1978年   2篇
  1977年   4篇
  1975年   2篇
  1970年   1篇
  1969年   3篇
  1968年   1篇
  1967年   1篇
  1965年   1篇
排序方式: 共有1809条查询结果,搜索用时 15 毫秒
21.

Aims

To study the impact of diabetic neuropathy, both peripheral sensorimotor (DPN) and cardiac autonomic neuropathy (CAN), on transcutaneous oxygen tension (TcPO2) in patients with type 2 diabetes mellitus (T2DM).

Methods

A total of 163 participants were recruited; 100 with T2DM and 63 healthy individuals. Peripheral arterial disease (PAD) was defined as ankle-brachial index (ABI) values ≤0.90. Diagnosis of DPN was based on neuropathy symptom score and neuropathy disability score (NDS), while diagnosis of CAN on the battery of the cardiovascular autonomic function tests. TcPO2 was measured using a TCM30 system.

Results

Patients with T2DM had lower TcPO2 levels when compared with healthy individuals. Among the diabetic cohort, those who had either PAD, DPN or CAN had significantly lower TcPO2 values than participants without these complications. Multivariate linear regression analysis, after controlling for diabetes duration, diastolic blood pressure, HbA1c, albumin to creatinine ratio and CAN score, demonstrated that TcPO2 levels were significantly and independently associated with current smoking (p?=?0.013), ABI (p?=?0.003), and NDS (p?=?0.013).

Conclusion

Presence of DPN is independently associated with impaired cutaneous perfusion. Low TcPO2 in subjects with DPN may contribute to delay in healing of diabetic foot ulcers, irrespectively of PAD.  相似文献   
22.
OBJECTIVE: Tamoxifen induced hepatotoxicity has not been investigated in breast cancer patients with pre-existing liver steatosis. The aim of our study was to investigate the most common predisposing factors for non-alcoholic fatty liver disease in breast cancer patients with liver steatosis, treated with adjuvant tamoxifen therapy, in order to evaluate their role in the appearance of tamoxifen induced hepatotoxicity. METHODS: Clinical and laboratory evaluation, including an oral glucose tolerance test, was done in 60 women with breast cancer and liver steatosis before the beginning of adjuvant tamoxifen treatment and every 6 months during treatment. Tamoxifen induced hepatotoxicity was defined as abnormal liver function tests during tamoxifen treatment whereas these test results were below the normal range at baseline control. Statistical evaluation of data was performed using parametric methodology (the chi-squared test, and Student's t-test, P < 0.05). RESULTS: Twenty-six patients (43.3%) exhibited tamoxifen induced hepatotoxicity (group A) whereas 34 (56.7%) did not (group B). The mean overall follow-up period for the whole group was 37.5 months (SD 27.8, range 6-120 months) and did not differ between the two groups (P = 0.055). There was significant statistical difference in body mass index (BMI) and baseline fasting glucose, cholesterol and triglyceride levels between the two groups. Eighteen of 26 patients (69.2%) from group A had impaired glucose tolerance compared with only 8/34 patients (23.5%) from group B (P < 0.001), a finding observed even in BMI matched patients from the two groups (62.5% vs 12.5%, P = 0.002). CONCLUSIONS: Tamoxifen induced hepatotoxicity is observed in a great proportion of breast cancer patients with pre-existing liver steatosis, especially those with higher BMI and higher glucose and lipid levels at baseline control. Glucose intolerance before the beginning of tamoxifen treatment seems to be a predictor of the hepatotoxicity, unrelated to baseline BMI.  相似文献   
23.
24.
25.
Clinical and Experimental Medicine - The new type of coronavirus (COVID-19), SARS-CoV-2 originated from Wuhan, China and has led to a worldwide pandemic. COVID-19 is a novel emerging infectious...  相似文献   
26.
To investigate age-related changes in oral motor strategies in response to unpredictable load demands. Sixty-five healthy children (aged 3–17 yr) were divided into five age-groups based on their dental eruption stages and compared with a group of healthy adults (aged 18–35 yr). Each participant was asked to perform a standardized motor control task involving ‘pulling’ and ‘holding’ a force transducer with the anterior teeth. Different loads were attached to the force transducer in an unpredictable manner. The temporal force profile was divided into two time-segments (an initial segment and a later segment). The peak force and peak force rate during the initial time-segment, and the holding force and intra-trial variability (coefficient of variation) during the later time-segment, were measured. The results showed no differences in the peak force, peak force rate, holding force, and force variability in children compared with adults. However, the trends in the data evaluated using a segmented regression analysis showed that a breakpoint (abrupt change) consistently occurred in the late-mixed dentition group (age 9–11 yr) for most of the outcome variables. The results indicate that while the motor control strategies in children appear to be similar to those in adults, there is a shift in the oral motor developmental trend during the late-mixed dentition stage.  相似文献   
27.
Worldwide, approximately 200 million people currently have type II diabetes mellitus (DM), a prevalence that has been predicted to increase to 366 million by 2030. Rates of cardiovascular disease (CVD) mortality and morbidity are particularly high in this population, representing a significant cost for health care systems. Type II DM patients generally carry a number of risk factors for CVD, including hyperglycemia, abnormal lipid profiles, alterations in inflammatory mediators and coagulation/thrombolytic parameters, as well as other 'nontraditional' risk factors, many of which may be closely associated with insulin resistance. Therefore, successful management of CVD associated with diabetes represents a major challenge to the clinicians. An effective way of tackling this problem is to detect the associated risk factors and to target treatment toward their improvement. Targeting hyperglycemia alone does not reduce the excess risk in diabetes, highlighting the need for aggressive treatment of other risk factors. Although the current use of statin therapy is effective at reducing low-density lipoprotein cholesterol, residual risk remains for other independent lipid and nonlipid factors. The peroxisome proliferator-activated receptor-gamma appears to be closely involved in regulating risk markers at multiple levels. A relatively new class of therapeutic agents that activate peroxisome proliferator-activated receptor-gamma, the thiazolidinedione insulin-sensitizing agents, is currently used to manage type II DM. These agents display a number of potential antiatherogenic properties, including effects on high-density lipoprotein cholesterol and triglycerides, as well as other beneficial nonlipid effects, such as regulating levels of mediators involved in inflammation and endothelial dysfunction. Research data suggest that simple strategies combining thiazolidinediones and statins could have complementary effects on CVD risk-factor profiles in diabetes, alongside the ability to control glycemia.  相似文献   
28.
Red blood cell (RBC) aging in the blood bank is characterized by the accumulation of a significant number of biochemical and morphologic alterations. Recent mass spectrometry and electron microscopy studies have provided novel insights into the molecular changes underpinning the accumulation of storage lesions to RBCs in the blood bank. Biochemical lesions include altered cation homeostasis, reprogrammed energy, and redox metabolism, which result in the impairment of enzymatic activity and progressive depletion of high‐energy phosphate compounds. These factors contribute to the progressive accumulation of oxidative stress, which in turn promotes oxidative lesions to proteins (carbonylation, fragmentation, hemoglobin glycation) and lipids (peroxidation). Biochemical lesions negatively affect RBC morphology, which is marked by progressive membrane blebbing and vesiculation. These storage lesions contribute to the altered physiology of long‐stored RBCs and promote the rapid clearance of up to one‐fourth of long‐stored RBCs from the recipient's bloodstream after 24 hours from administration. While prospective clinical evidence is accumulating, from the present review it emerges that biochemical, morphologic, and omics profiles of stored RBCs have observable changes after approximately 14 days of storage. Future studies will assess whether these in vitro observations might have clinically meaningful effects.  相似文献   
29.
According to the established validation protocols, a typical validation study of a blood pressure (BP) monitor includes general population adults with normal or elevated BP. It is recognized, however, that the automated (oscillometric) BP monitors may have different accuracy or uses in some special populations compared with adults in the general population. Thus, an automated BP monitor with proven accuracy in a general population of adults may not be accurate in a special population, and therefore separate validation is needed. Recognized special populations deserving separate validation are those for which there is theoretical, and also clinical evidence, that the accuracy of BP monitors in these groups differs from that in the general population. Young children, pregnant women (including those with preeclampsia), individuals with arm circumference >42 cm, and patients with atrial fibrillation are regarded as special populations. Adolescents, individuals older than 80 years, and patients with end‐stage renal disease or diabetes mellitus have also been considered as possible special groups, but there is still inadequate evidence of altered accuracy of BP monitors in these subjects. Validation studies should be performed in special populations and evaluated separately after the BP‐measuring device has successfully undergone a validation study in a general population (unless the test device is intended only for a special population). This article discusses issues relating to the measurement of BP and the diagnosis of hypertension in selected special populations, as well as in low‐resource settings, where a simplified yet efficient evaluation strategy is necessary.  相似文献   
30.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号